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United States Patent 3,025,799 IMMERSIBLE DRAINAGE PUMPS Stig LennartHallerbick, Sodertalje, Sweden, assignor to Alrtlebolaget W. DanBergman, Sodertalje, Sweden, 21 joint-stool: company of Sweden FiledDec. 30, 1959, Ser. No. 862,823 Claims. (Cl. 103-87) This inventionrelates to pumps, and particularly to immersible drainage pumps. 2

It is an object of the invention to provide in an immersible drainagepump having an inner casing enclosing an electric drive motor, an outercasing enclosing a bladed pump impeller and assembled of a number ofcomponents which are shaped and joined in such a way as to readilypermit the exchange of the impeller and associated par-ts to make thepump suited to different operating conditions.

With this and other objects in view, I provide an immersible drainagepump comprising an outer casing, an inner casing, a bladed pump impellerdisposed within said outer casing and an electric drive motor disposedwithin said inner casing and connected to rotate said impeller to makethe latter induce a flow of fluid which is drawn into said outer casingat the bottom thereof, is propelled upwards through a passage betweensaid inner and said outer casing, and is delivered from the top of saidouter casing, said outer casing being formed of three components, onebase member, one intermediate member, and one top member, saidcomponents being joined together along planes perpendicular to the pumpaxis, said base member extending from the bottom of said outer casingand having its upper end level with the bottom end of said inner casing,said base member forming an impeller casing and being joined to saidintermediate casing member through means of fixation such as boltmembers, there being fluid inlet ports in said impeller casing and fluidflow guiding means such as guide vanes upstream and downstream theimpeller, said top casing member extending from said intermediate casingmember and detachably secured to the latter with means of fixation suchas bolt members, said intermediate member being comparatively low andbeing secured to the bottom end portion of said inner casing by strutmeans integral with said intermediate member and said inner casing.

Preferred embodiments of the invention will be described hereinafter,reference being had to the accompanying drawings.

FIG. 1 is a sectional elevation through a drainage pump according to theinvention.

FIG. 2 is a cross section view of the outer and inner casing at thelevel of the drive motor.

FIG. 3 is a sectional elevation of the bottom portion of a drainage pumpprovided with an impeller of a modified shape.

FIG. 4 is a sectional elevation similar to that in FIG. 3, andillustrating the base portion of a drainage pump provided with a dividedtwo-stage impeller.

Referring to FIG. 1 the pump illustrated therein comprises an outercasing 1 and an inner casing 2, the latter enclosing an electric drivemotor with associated shaft bearing and sealing means. The motor driveshaft 3 protruding from the inner casing 2 at its lower end carries abladed pump impeller 4. The drive motor, the shaft bearing means andshaft sealing means will not be specifically described as they form nopart of the present invention.

The outer casing 1 is formed of an upper member 5, an intermediatemember 6 and a base member 7, the latter affording an impeller housing.The outer casing is separated into the said three members along planesperpendicular to the vertical longitudinal axis of the pump. The uppercasing member 5 is joined to the intermediate member 6 by means of boltsor screws (not illustrated) in a manner known in itself, and theintermediate and base members 6, 7 are joined together in a similar way.The outer casing consequently forms a rigid supporting structure. Theinterconnecting bolts or screws preferably are disposed within thecasing. The plane of division between the impeller housing and theintermediate member 6 lies substantially on a level with the bottom ofthe inner casing, and also with the top of the impeller, the latterbeing accommodated completely within its housing 7. In the impellerhousing 7 inlet guide vanes 8 and preferably also outlet guide vanes 9are provided, and further a cylindrical strainer 10 is disposed aroundthe lower portion of the housing to prevent solid matter to enter theimpeller and obstruct the pump. The strainer 10 is retained in itsposition by a bottom plate 11, detachably secured to the impellerhousing as by screw means.

The intermediate casing member 6 is connected to the inner casing 2 bymeans of radially extending struts 12 which are formed integrally withsaid members and preferably are shaped as downstream extensions ofoutlet guide vanes '9.

To further improve the fluid flow through the pump, guide ribs 13 areprovided in the annular passage between the inner and outer casing, saidribs being preferably formed integral with the inner casing. Those ribsextend across the annular passage and preferably along the whole lengthof the inner casing 2. As illustrated in FIG. 2 the ribs '13 may behollow with their interior space communicating with the air space withinthe inner casing which will improve the air cooling of the statorwindings disposed within the inner casing.

In order to adapt the pump to altered operating conditions the impellerand the impeller housing with associated guide vanes may'easily beexchanged against other corresponding elements which are suited to thosenew conditions. In such case the strainer .10 and the bottom plate 11need not be exchanged since those elements, as

i will also be evident from FIGS. 1, 3 and 4, are common to all impellerhousings.

When the impeller and guide vanes shall be changed, the parts 11 and .10are first removed, and thereafter the impeller housing 7 is detached byremoving the screws or bolts securing it to the intermediate member 6.After the impeller 4 has been detached from the shaft 3, anotherimpeller 4' is secured to the latter, and an impeller housing 7belonging to the new impeller is secured to the casing member 6. Thestrainer 10 and bottom plate 11 are mounted, and the exchange iscompleted, FIG. 3.

FIG. 4 illustrates the invention as applied to a pump provided with atwo-stage impeller 4". The said impeller is divided radially between thestages in two portions, one upper portion 14 and one lower portion 15.The impeller housing 7" is divided likewise into two portions, one topportion 16 and one larger bottom portion 17. The latter is provided asusual with the strainer 10 and the bottom plate 11. The intermediatecasing member 6 and members 16 and 17 are joined by suitable bolts orthe like (not illustrated). The bottom portion 17 of the impellerhousing 7" is more or less similar to the impeller housing describedabove, and comprises inlet guide vanes 8 and outlet guide vanes 9". Theupper impeller casing portion 16 is likewise provided with inlet guidevanes 18 and outlet guide vanes 19. Furthermore, the impeller casingportion 16 or -17 may be formed with an intermediate annular member 20affording a circumferential extension of the lower impeller portion, andassisting in guiding the fluid fiow through the impeller.

Other embodiments and different modifications of details will be obviousto those skilled in the art, and will fall well within the scope of theinvention such as expressed in the appended claims.

What I claim is:

1. An immersible drainage pump comprising an outer casing, an innercasing, a bladed pump impeller disposed within said outer casing and anelectric drive motor disposed within said inner casing and connected torotate said impeller, said inner and outer casings being arranged toprovide a passage therebetween, said outer casing being formed of threecomponents, a base member, an intermediate member forming also a closurefor said inner casing, and a top member including a discharge opening,said components being joined together along planes perpendicular to thepump axis, said base member extending from the bottom of said outercasing and having its upper end approximately level with the bottom endof said inner casing, said base member forming an impeller casing joinedto said intermediate casing member by means of bolt members, fluid inletports in said impeller casing and fluid flow guiding vanes both upstreamand downstream of the impeller, said top outer casing member extendingfrom said intermediate casing member and detachably secured to thelatter by means of bolt members, said intermediate member being ofcomparatively short axial length and being secured to the bottom endportion of said inner casing by strut means integral with saidintermediate member and with said inner casing, said strut means formingextensions in the flow direction of said guide vanes downstream of saidimpeller, said casing being formed with radially disposed rib membersextending across the passage between said inner and said outer casing,and being provided along the whole length of said inner casing, said ribmembers being aligned with said strut means, and serving to furtherguide the fluid flow.

2. An immersible drainage pump as claimed in claim 1, wherein said ribmembers are hollow to allow air circulation therethrough to facilitatethe cooling of the interior of said inner casing, and the electric drivemotor disposed therein.

3. An immersible drainage pump as claimed in claim 2, wherein said basemember forming the impeller casing is formed with a cylindricalperforated circumferential wall forming a strainer for the fluid to bepumped, and a bottom plate detachably secured to said base member andretaining said perforated wall in its desired position.

4. In an immersible drainage pump comprising an outer casing, an innercasing within said outer casing, a bladed pump impeller disposed withinsaid outer casing and an electric drive motor disposed within said innercasing and connected to rotate said impeller, the walls of said casingsbeing spaced to provide a passage therebetween, said outer casing beingformed of three components, a base member, an intermediate membercarrying a closure portion for said inner casing, and a top member, saidcomponents being joined together along planes perpendicular to the pumpaxis, said base member extending from the bottom of said outer casingand having its upperend substantially level with the bottom end of saidinner casing, said base member forming an impeller casing and beingjoined to said intermediate casing member by means of bolt members,fluid inlet ports in said base member forming said impeller casing andfluid flow guide vanes both upstream and downstream of the impeller,said top outer casing member extending from said intermediate casingmember and detachably secured to the latter by means of bolt members,said intermediate member being or comparatively little axial length andbeing secured to the portion thereof forming the closure of said innercasing by strut means integral with said intermediate member and saidclosure portion, said guide means comprising outlet guide vanesdownstream ofsaid impeller, said strut means of said intermediate memberforming extensions in the flow direction of said guide vanes, said innercasing being formed with radially disposed rib members extending acrossthe passage between said inner and said outer casing extendingessentially along the whole length of said inner casing, said rib meansbeing aligned with said strut means and serving to further guide thefluid flow, said bladed impeller being a two-stage impeller dividedalong a plane between the stages, and said impeller casing being alsodivided into two portions, a lower main portion provided with inlet andoutlet guide vanes, and an upper portion extending between the impellerstages, and provided with inlet and outlet guide means.

5. In animmersible drainage pump comprising an outer casing, an innercasing, a bladed pump impeller disposed within said outer casing and anelectric drive motor disposed within said inner casing and connected.

to rotate said impeller, said outer casing being formed of threecomponents, one base member, one intermediate member, and one topmember, said components being joined together along planes perpendicularto the pump axis, said base member extending from the bottom of saidouter casing and having its upper end adjacent the bottom end of saidinner casing, said base member forming an impeller casing and beingjoined to said intermediate casing member by means of bolts, fluid inletports in said impeller casing and guide vanes upstream and down streamof the impeller, said top casing member extending from said intermediatecasing member and detachably secured to the latter by means of bolts,said intermediate member being of comparatively little axial length andbeing secured to the bottom end portion of said inner casing by strutmeans integral with said intermediate member and said inner casing, saidguide means comprising outlet guide vanes downstream of said impeller,and said strut means forming extensions in the flow direction of saidguide vanes, said inner casing being formed with i radially disposed ribmembers extending across the passage between said inner and said outercasing, and being provided along substantially the whole length of saidinner casing, said rib means being aligned with said strut means, andserving to further guide the fluid flow, said bladed impeller being atwo-stage impeller divided along a plane between the stages, and saidimpeller casing being also divided into two portions, a lower mainportion provided with inlet and outlet guide vanes, and an upper portionextending between the impeller stages provided with inlet and outletguide means, and an annular member provided as a circumferentialextension of that impeller stage closest to the pump inlet for assistingin guiding the pumping fluid through the impeller.

References Cited in the file of this patent UNITED STATES PATENTS1,366,589 Ostenberg Jan. 25, 1921 1,387,660 Ostenberg Aug, 16, 19211,884,573 Chapman Oct. 25, 1932 1,974,183 Gunderson Sept. 18, 19342,130,583 Fosnot Sept. 20, 1938 2,423,436 Blom July 8, 1947 2,492,141Gaylord Dec. 27, 1949 2,689,529 Wightrnan Sept. 21, 1954 2,921,532Tsiguloff Jan. 19, 1960

